1. Field of the Invention
The present invention relates to a vibration-absorbing plate for a golf club head. In particular, the present invention relates to a vibration-absorbing plate for gaining damping effect of the body of the golf club head to thereby effectively absorb the vibrations generated as a result of striking a golf ball.
2. Description of Related Art
U.S. Pat. No. 5,967,903 discloses a golf club head with a sandwich structure and a method of making the same. As illustrated in FIG. 1 of the drawings which corresponds to FIG. 3 of U.S. Pat. No. 5,967,903, the golf club head includes a body 10, a striking assembly consisting of a front member 20 and a rear member 21. The body 10 is made of stainless steel or the like. Further, the body 10 includes a groove 17, a rear cavity 11, and an aperture 16 which connects the groove 17 to the rear cavity 11. The front member 20 and the rear member 21 are inserted via a front side of the body 10 into the groove 17 and fixed on a stepped portion 12 of the body 10. The front member 20 is formed from a relatively hard material (such as maraging steel, titanium alloy, etc.), and the rear member 21 is formed from a relatively soft material (such as aluminum, bronze, etc.). The rear member 21 damps impact generated vibrations, thereby improving gripping comfort and improving striking accuracy.
The rear member 21 and the front member 20 would elastically deform and reciprocatingly vibrate in a synchronous manner until completely stopped. However, according to dynamic analysis, the rear member 21 in a dynamic state contributed far less than the front member 20 in a static state did. Namely, the vibration-absorbing capacity of the golf club head largely depends on the damping value of the golf club head itself and has little concern with the composite structure consisting of the front member 20 and the rear member 21. Further, the rear member 21 tightly engaged to the rear side of the front member 20 restrains the elastic deformation of the front member 20. The striking effect of the front member 20 (i.e., the flying distance of a golf ball stricken by the front member 20) is adversely affected. Further, the front member 20 and the rear member 21 are formed of different materials and thus have different coefficients of elastic deformation. Thus, after striking golf balls for several times, deformation of the front member 20 would be different from that of the rear member 21. Consequently, the front member 20 and the rear member 21 are apt to disengage from each other. As a result, the front member 20 and the rear member 21 impact each other and thus generate odd sound while striking.
In a case that the front member 20 and the rear member 21 are bonded together by adhesive, the composite structure of front member 20/rear member 21 is not suitable for conventional welding procedures for engaging the composite structure with the body 10. Although the front member 20 and the rear member 21 can be tightly engaged together by explosive welding, the cost is largely increased. Further, the rear member 21 sandwiched between the step portion 12 of the body 10 and the front member 20 and formed from a relatively soft material is plastic and thus would plastically deform, adversely affecting the bonding reliability among the body 10, the front member 20, and the rear member 21. Undesired disengagement may occur, undesired gap and/or odd sound during striking may be generated, and what is worse, the front member 20 and the rear member 21 may be disengaged from the body 10.